Stacked chip package structure and manufacturing method thereof

Abstract

A manufacturing method of a stacked chip package structure includes the following steps. A first chip is disposed on a carrier, wherein the first chip has a first active surface and a plurality of first pads disposed on the first active surface. A second chip is disposed on the first chip without covering the first pads and has a second active surface and a plurality of second pads disposed on the second active surface. A plurality of first stud bumps are formed on the first pads. A plurality of pillar bumps are formed on the second pads. The first chip and the second chip are encapsulated by an encapsulant, wherein the encapsulant exposes a top surface of each second stud bump. A plurality of first vias are formed by a laser process, wherein the first vias penetrate the encapsulant and expose the first stud bumps. A conductive layer is formed in the first vias to form a plurality of first conductive vias. The carrier is removed.

What is claimed is: 
     
       1. A manufacturing method of a stacked chip package structure, comprising:
 disposing a first chip on a carrier, wherein the first chip has a first active surface and a plurality of first pads disposed on the first active surface; 
 disposing a second chip on the first chip, wherein the second chip exposes the first pads and has a second active surface and a plurality of second pads disposed on the second active surface; 
 forming a plurality of first stud bumps on the first pads; 
 forming a plurality of pillar bumps on the second pads; 
 encapsulating the first chip and the second chip by an encapsulant, wherein the encapsulant exposes a top surface of each of the pillar bumps; 
 forming a plurality of first vias by a laser process, wherein the first vias penetrate the encapsulant and expose the first stud bumps; 
 forming a recessed area on each of the first stud bumps by the laser process; 
 roughening a surface of the recessed area of each of the first stud bumps by the laser process to form a rough surface; 
 forming a conductive layer in the first vias to form a plurality of first conductive vias, wherein after forming the conductive layer in the first vias to form the plurality of first conductive vias, the conductive layer at least partially conforms to the rough surface of each of the first stud bumps; and 
 removing the carrier, wherein a shape of the plurality of first stud bumps before the step of encapsulating the first chip and the second chip by the encapsulant is substantially the same as a shape of the plurality of first stud bumps after the step of forming the conductive layer in the first vias to form the plurality of first conductive vias, and each of the plurality of first stud bumps includes a protruded knot before the step of encapsulating the first chip and the second chip by the encapsulant. 
 
     
     
       2. The manufacturing method of the stacked chip package structure as claimed in  claim 1 , further comprising:
 forming a redistribution layer on the encapsulant, wherein the redistribution layer comprises a circuit layer electrically connected to the first chip and the second chip through the first conductive vias and the pillar bumps. 
 
     
     
       3. The manufacturing method of the stacked chip package structure as claimed in  claim 2 , further comprising:
 forming a passivation layer on the redistribution layer, wherein the passivation layer comprises a plurality of openings exposing a part of the redistribution layer. 
 
     
     
       4. The manufacturing method of the stacked chip package structure as claimed in  claim 3 , further comprising:
 forming a plurality of solder balls on the openings of the passivation layer, wherein the solder balls are electrically connected to the circuit layer. 
 
     
     
       5. The manufacturing method of the stacked chip package structure as claimed in  claim 1 , further comprising:
 forming a shielding layer on an outer surface of the encapsulant. 
 
     
     
       6. The manufacturing method of the stacked chip package structure as claimed in  claim 1 , wherein a top surface of each of the first stud bumps is roughened by the laser process to form a rough surface, and the conductive layer covers the rough surface of each of the first stud bumps. 
     
     
       7. The manufacturing method of the stacked chip package structure as claimed in  claim 1 , further comprising:
 disposing a third chip on the first chip without covering the first pads before the second chip is disposed on the first chip, wherein the third chip has a third active surface and a plurality of third pads disposed on the third active surface, and the second chip is disposed on the third chip without covering the third pads; 
 forming a plurality of second stud bumps on the third pads; and 
 forming a plurality of second conductive vias penetrating the encapsulant and coupled to the second stud bumps. 
 
     
     
       8. The manufacturing method of the stacked chip package structure as claimed in  claim 1 , wherein the number of the first chip is plural, the first chips are arranged in a side-by-side manner, and the second chip is disposed on the first chips. 
     
     
       9. The manufacturing method of the stacked chip package structure as claimed in  claim 8 , further comprising:
 disposing a plurality of third chips on the first chips without covering the first pads of the first chips before the second chip is disposed on the first chips, wherein each of the third chips has a third active surface and a plurality of third pads disposed on the third active surface, and the second chip is disposed on the third chips without covering the third pads of the third chips; 
 forming a plurality of second stud bumps on the third pads; and 
 forming a plurality of second conductive vias penetrating the encapsulant and coupled to the second stud bumps. 
 
     
     
       10. The manufacturing method of the stacked chip package structure as claimed in  claim 1 , wherein the conductive layer completely covers the rough surface of each of the first stud bumps. 
     
     
       11. The manufacturing method of the stacked chip package structure as claimed in  claim 1 , wherein each of the first conductive vias protrudes into the recessed area of a corresponding first stud bump and at least partially conforms to the rough surface of the corresponding first stud bump. 
     
     
       12. The manufacturing method of the stacked chip package structure as claimed in  claim 1 , wherein the encapsulant completely covers the sidewalls of the first conductive vias, and there is no interface in the encapsulant. 
     
     
       13. The manufacturing method of the stacked chip package structure as claimed in  claim 1 , wherein each of the plurality of first stud bumps includes only one protruded knot before the step of encapsulating the first chip and the second chip by the encapsulant.